Re: [PATCH v2 2/2] thermal: uniphier: add UniPhier thermal driver

From: Eduardo Valentin
Date: Fri Jun 30 2017 - 23:17:32 EST


Hey,

On Wed, Jun 28, 2017 at 07:11:59PM +0900, Kunihiko Hayashi wrote:
> Add a thermal driver for on-chip PVT (Process, Voltage and Temperature)
> monitoring unit implemented on UniPhier SoCs. This driver supports
> temperature monitoring and alert function.
>
> Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx>
> ---
> drivers/thermal/Kconfig | 8 +
> drivers/thermal/Makefile | 1 +
> drivers/thermal/uniphier_thermal.c | 391 +++++++++++++++++++++++++++++++++++++
> 3 files changed, 400 insertions(+)
> create mode 100644 drivers/thermal/uniphier_thermal.c
>
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index 776b343..6631826 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -453,4 +453,12 @@ config ZX2967_THERMAL
> the primitive temperature sensor embedded in zx2967 SoCs.
> This sensor generates the real time die temperature.
>
> +config UNIPHIER_THERMAL
> + tristate "Socionext UniPhier thermal driver"
> + depends on ARCH_UNIPHIER || COMPILE_TEST
> + depends on THERMAL_OF && MFD_SYSCON
> + help
> + Enable this to plug in UniPhier on-chip PVT thermal driver into the
> + thermal framework. The driver supports CPU thermal zone temperature
> + reporting and a couple of trip points.
> endif
> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
> index 7adae20..05b6e7c 100644
> --- a/drivers/thermal/Makefile
> +++ b/drivers/thermal/Makefile
> @@ -58,3 +58,4 @@ obj-$(CONFIG_HISI_THERMAL) += hisi_thermal.o
> obj-$(CONFIG_MTK_THERMAL) += mtk_thermal.o
> obj-$(CONFIG_GENERIC_ADC_THERMAL) += thermal-generic-adc.o
> obj-$(CONFIG_ZX2967_THERMAL) += zx2967_thermal.o
> +obj-$(CONFIG_UNIPHIER_THERMAL) += uniphier_thermal.o
> diff --git a/drivers/thermal/uniphier_thermal.c b/drivers/thermal/uniphier_thermal.c
> new file mode 100644
> index 0000000..7664f58
> --- /dev/null
> +++ b/drivers/thermal/uniphier_thermal.c
> @@ -0,0 +1,391 @@
> +/**
> + * uniphier_thermal.c - Socionext UniPhier thermal driver
> + *
> + * Copyright 2014 Panasonic Corporation
> + * Copyright 2016-2017 Socionext Inc.
> + * All rights reserved.
> + *
> + * Author:
> + * Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx>
> + *
> + * This program is free software: you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 of
> + * the License as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/interrupt.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/thermal.h>
> +
> +#include "thermal_core.h"
> +
> +/*
> + * block registers
> + * addresses are the offset from .block_base
> + */
> +#define PVTCTLEN 0x0000
> +#define PVTCTLEN_EN BIT(0)
> +
> +#define PVTCTLMODE 0x0004
> +#define PVTCTLMODE_MASK 0xf
> +#define PVTCTLMODE_TEMPMON 0x5
> +
> +#define EMONREPEAT 0x0040
> +#define EMONREPEAT_ENDLESS BIT(24)
> +#define EMONREPEAT_PERIOD GENMASK(3, 0)
> +#define EMONREPEAT_PERIOD_1000000 0x9
> +
> +/*
> + * common registers
> + * addresses are the offset from .map_base
> + */
> +#define PVTCTLSEL 0x0900
> +#define PVTCTLSEL_MASK GENMASK(2, 0)
> +#define PVTCTLSEL_MONITOR 0
> +
> +#define SETALERT0 0x0910
> +#define SETALERT1 0x0914
> +#define SETALERT2 0x0918
> +#define SETALERT_TEMP_OVF (GENMASK(7, 0) << 16)
> +#define SETALERT_TEMP_OVF_VALUE(val) (((val) & GENMASK(7, 0)) << 16)
> +#define SETALERT_EN BIT(0)
> +
> +#define PMALERTINTCTL 0x0920
> +#define PMALERTINTCTL_CLR(ch) BIT(4 * (ch) + 2)
> +#define PMALERTINTCTL_SET(ch) BIT(4 * (ch) + 1)
> +#define PMALERTINTCTL_EN(ch) BIT(4 * (ch) + 0)
> +#define PMALERTINTCTL_MASK (GENMASK(10, 8) | GENMASK(6, 4) | \
> + GENMASK(2, 0))
> +
> +#define TMOD 0x0928
> +#define TMOD_MASK GENMASK(9, 0)
> +
> +#define TMODCOEF 0x0e5c
> +
> +#define TMODSETUP0_EN BIT(30)
> +#define TMODSETUP0_VAL(val) (((val) & GENMASK(13, 0)) << 16)
> +#define TMODSETUP1_EN BIT(15)
> +#define TMODSETUP1_VAL(val) ((val) & GENMASK(14, 0))
> +
> +/* SoC critical temperature */
> +#define CRITICAL_TEMP_LIMIT (120 * 1000)
> +
> +/* Max # of alert channels */
> +#define ALERT_CH_NUM 3
> +
> +/* SoC specific thermal sensor data */
> +struct uniphier_tm_soc_data {
> + u32 map_base;
> + u32 block_base;
> + u32 tmod_setup_addr;
> +};
> +
> +struct uniphier_tm_dev {
> + struct regmap *regmap;
> + bool alert_en[ALERT_CH_NUM];
> + u32 tmod_calib0;
> + u32 tmod_calib1;
> + struct thermal_zone_device *tz_dev;
> + const struct uniphier_tm_soc_data *data;
> +};
> +
> +static int uniphier_tm_initialize_sensor(struct uniphier_tm_dev *tdev)
> +{
> + struct regmap *map = tdev->regmap;
> + u32 val;
> + int ret;
> +
> + /* stop PVT */
> + regmap_write_bits(map, tdev->data->block_base + PVTCTLEN,
> + PVTCTLEN_EN, 0);
> +
> + /*
> + * set default value if missing calibrated value
> + *
> + * Since SoC has a calibrated value that was set in advance,
> + * TMODCOEF shows non-zero and PVT refers the value internally.
> + *
> + * However, some boards don't have the calibrated value.
> + * In that case, TMODCOEF shows zero and the driver has to set
> + * default value manually.
> + */
> + ret = regmap_read(map, tdev->data->map_base + TMODCOEF, &val);
> + if (ret)
> + return ret;
> + if (!val)
> + regmap_write(map, tdev->data->tmod_setup_addr,
> + TMODSETUP0_EN | TMODSETUP0_VAL(tdev->tmod_calib0) |
> + TMODSETUP1_EN | TMODSETUP1_VAL(tdev->tmod_calib1));
> +
> + /* select temperature mode */
> + regmap_write_bits(map, tdev->data->block_base + PVTCTLMODE,
> + PVTCTLMODE_MASK, PVTCTLMODE_TEMPMON);
> +
> + /* set monitoring period */
> + regmap_write_bits(map, tdev->data->block_base + EMONREPEAT,
> + EMONREPEAT_ENDLESS | EMONREPEAT_PERIOD,
> + EMONREPEAT_ENDLESS | EMONREPEAT_PERIOD_1000000);
> +
> + /* set monitor mode */
> + regmap_write_bits(map, tdev->data->map_base + PVTCTLSEL,
> + PVTCTLSEL_MASK, PVTCTLSEL_MONITOR);
> +
> + return 0;
> +}
> +
> +static void uniphier_tm_set_alert(struct uniphier_tm_dev *tdev, u32 ch,
> + u32 temp)
> +{
> + struct regmap *map = tdev->regmap;
> +
> + /* set alert temperature */
> + regmap_write_bits(map, tdev->data->map_base + SETALERT0 + (ch << 2),
> + SETALERT_EN | SETALERT_TEMP_OVF,
> + SETALERT_EN |
> + SETALERT_TEMP_OVF_VALUE(temp / 1000));
> +}
> +
> +static void uniphier_tm_enable_sensor(struct uniphier_tm_dev *tdev)
> +{
> + struct regmap *map = tdev->regmap;
> + int i;
> + u32 bits = 0;
> +
> + for (i = 0; i < ALERT_CH_NUM; i++)
> + if (tdev->alert_en[i])
> + bits |= PMALERTINTCTL_EN(i);
> +
> + /* enable alert interrupt */
> + regmap_write_bits(map, tdev->data->map_base + PMALERTINTCTL,
> + PMALERTINTCTL_MASK, bits);
> +
> + /* start PVT */
> + regmap_write_bits(map, tdev->data->block_base + PVTCTLEN,
> + PVTCTLEN_EN, PVTCTLEN_EN);

Do we need to wait some time after starting PVT and before reading the
first temperature?

> +}
> +
> +static void uniphier_tm_disable_sensor(struct uniphier_tm_dev *tdev)
> +{
> + struct regmap *map = tdev->regmap;
> +
> + /* disable alert interrupt */
> + regmap_write_bits(map, tdev->data->map_base + PMALERTINTCTL,
> + PMALERTINTCTL_MASK, 0);
> +
> + /* stop PVT */
> + regmap_write_bits(map, tdev->data->block_base + PVTCTLEN,
> + PVTCTLEN_EN, 0);
> +}
> +
> +static int uniphier_tm_get_temp(void *data, int *out_temp)
> +{
> + struct uniphier_tm_dev *tdev = data;
> + struct regmap *map = tdev->regmap;
> + int ret;
> + u32 temp;
> +
> + ret = regmap_read(map, tdev->data->map_base + TMOD, &temp);
> + if (ret)
> + return ret;
> +
> + /*
> + * Since MSB of TMOD_MASK in TMOD represents signed bit,
> + * if the register value is bigger than or equal to
> + * ((TMOD_MASK + 1) / 2), it represents a negative value
> + * of temperature.
> + */
> + temp &= TMOD_MASK;
> + if (temp >= ((TMOD_MASK + 1) / 2))
> + *out_temp = (temp - (TMOD_MASK + 1)) * 1000;

But, why do you mask negative values? Are you considering them invalid?
should this be reported? Why simply silently transforming into positive?

> + else
> + *out_temp = temp * 1000; /* millicelsius */
> +
> + return 0;
> +}
> +
> +static const struct thermal_zone_of_device_ops uniphier_of_thermal_ops = {
> + .get_temp = uniphier_tm_get_temp,
> +};
> +
> +static void uniphier_tm_irq_clear(struct uniphier_tm_dev *tdev)
> +{
> + u32 mask = 0, bits = 0;
> + int i;
> +
> + for (i = 0; i < ALERT_CH_NUM; i++) {
> + mask |= (PMALERTINTCTL_CLR(i) | PMALERTINTCTL_SET(i));
> + bits |= PMALERTINTCTL_CLR(i);
> + }
> +
> + /* clear alert interrupt */
> + regmap_write_bits(tdev->regmap,
> + tdev->data->map_base + PMALERTINTCTL, mask, bits);
> +}
> +
> +static irqreturn_t uniphier_tm_alarm_irq(int irq, void *_tdev)
> +{
> + struct uniphier_tm_dev *tdev = _tdev;
> +
> + disable_irq_nosync(irq);
> + uniphier_tm_irq_clear(tdev);
> +
> + return IRQ_WAKE_THREAD;
> +}
> +
> +static irqreturn_t uniphier_tm_alarm_irq_thread(int irq, void *_tdev)
> +{
> + struct uniphier_tm_dev *tdev = _tdev;
> +
> + thermal_zone_device_update(tdev->tz_dev, THERMAL_EVENT_UNSPECIFIED);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int uniphier_tm_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct regmap *regmap;
> + struct device_node *parent;
> + struct uniphier_tm_dev *tdev;
> + const struct thermal_trip *trips;
> + const u32 *calib;
> + int i, ret, irq, ntrips, crit_temp = INT_MAX;
> +
> + tdev = devm_kzalloc(dev, sizeof(*tdev), GFP_KERNEL);
> + if (!tdev)
> + return -ENOMEM;
> +
> + tdev->data = of_device_get_match_data(dev);
> + if (WARN_ON(!tdev->data))
> + return -EINVAL;
> +
> + irq = platform_get_irq(pdev, 0);
> + if (irq < 0)
> + return irq;
> +
> + /* get tmod-calibration values */
> + calib = of_get_property(dev->of_node, "socionext,tmod-calibration",
> + NULL);
> + if (calib) {
> + tdev->tmod_calib0 = of_read_number(calib, 1);
> + tdev->tmod_calib1 = of_read_number(calib + 1, 1);
> + }
> +
> + /* get regmap from syscon node */
> + parent = of_get_parent(dev->of_node); /* parent should be syscon node */
> + regmap = syscon_node_to_regmap(parent);
> + of_node_put(parent);
> + if (IS_ERR(regmap)) {
> + dev_err(dev, "failed to get regmap (error %ld)\n",
> + PTR_ERR(regmap));
> + return PTR_ERR(regmap);
> + }
> + tdev->regmap = regmap;
> +
> + ret = uniphier_tm_initialize_sensor(tdev);
> + if (ret) {
> + dev_err(dev, "failed to initialize sensor\n");
> + return ret;
> + }
> +
> + ret = devm_request_threaded_irq(dev, irq, uniphier_tm_alarm_irq,
> + uniphier_tm_alarm_irq_thread,
> + 0, "thermal", tdev);
> + if (ret)
> + return ret;
> +
> + platform_set_drvdata(pdev, tdev);
> +
> + tdev->tz_dev = devm_thermal_zone_of_sensor_register(dev, 0, tdev,
> + &uniphier_of_thermal_ops);
> + if (IS_ERR(tdev->tz_dev)) {
> + dev_err(dev, "failed to register sensor device\n");
> + return PTR_ERR(tdev->tz_dev);
> + }
> +
> + /* get trip points */
> + trips = of_thermal_get_trip_points(tdev->tz_dev);
> + ntrips = of_thermal_get_ntrips(tdev->tz_dev);
> + if (ntrips > ALERT_CH_NUM) {
> + dev_err(dev, "thermal zone has too many trips\n");
> + return -E2BIG;
> + }
> +
> + /* set alert temperatures */
> + for (i = 0; i < ntrips; i++) {
> + if (trips[i].type == THERMAL_TRIP_CRITICAL &&
> + trips[i].temperature < crit_temp)
> + crit_temp = trips[i].temperature;
> + uniphier_tm_set_alert(tdev, i, trips[i].temperature);
> + tdev->alert_en[i] = true;
> + }
> + if (crit_temp > CRITICAL_TEMP_LIMIT) {
> + dev_err(dev, "critical trip is over limit(>%d), or not set\n",
> + CRITICAL_TEMP_LIMIT);
> + return -EINVAL;
> + }
> +
> + uniphier_tm_enable_sensor(tdev);
> +
> + return 0;
> +}
> +
> +static int uniphier_tm_remove(struct platform_device *pdev)
> +{
> + struct uniphier_tm_dev *tdev = platform_get_drvdata(pdev);
> +
> + /* disable sensor */
> + uniphier_tm_disable_sensor(tdev);
> +
> + return 0;
> +}
> +
> +static const struct uniphier_tm_soc_data uniphier_pxs2_tm_data = {
> + .map_base = 0xe000,
> + .block_base = 0xe000,
> + .tmod_setup_addr = 0xe904,
> +};
> +
> +static const struct uniphier_tm_soc_data uniphier_ld20_tm_data = {
> + .map_base = 0xe000,
> + .block_base = 0xe800,
> + .tmod_setup_addr = 0xe938,
> +};
> +
> +static const struct of_device_id uniphier_tm_dt_ids[] = {
> + {
> + .compatible = "socionext,uniphier-pxs2-thermal",
> + .data = &uniphier_pxs2_tm_data,
> + },
> + {
> + .compatible = "socionext,uniphier-ld20-thermal",
> + .data = &uniphier_ld20_tm_data,
> + },
> + { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, uniphier_tm_dt_ids);
> +
> +static struct platform_driver uniphier_tm_driver = {
> + .probe = uniphier_tm_probe,
> + .remove = uniphier_tm_remove,
> + .driver = {
> + .name = "uniphier-thermal",
> + .of_match_table = uniphier_tm_dt_ids,
> + },
> +};
> +module_platform_driver(uniphier_tm_driver);
> +
> +MODULE_AUTHOR("Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("UniPhier thermal driver");
> +MODULE_LICENSE("GPL v2");
> --
> 2.7.4
>